This program is focused on the study of enzyme systems for the biosynthesis and oxidative decarboxylation of 2-hydroxy fatty acids in the brain. In recent preliminary experiments, we have for the first time demonstrated the in vitro biosynthesis of brain 2-hydroxy fatty acid. We will attempt to solubilize, purify, and characterize these enzymes. The effects of various controlling factors, such as aging, hormones, and drugs will be studied. We will attempt to separate the enzyme which converts 2-hydroxy fatty acids to 2-keto acids from that which catalyzes further oxidative decarboxylation. The unique features of the assay for 2-hydroxy acid biosynthesis in this proposal are: (1) use of 1-C14-lignoceric acid which is the major natural substrate of the enzyme and which we believe, therefore, has more affinity for the enzyme than the commonly available 1-C14-stearic acid, (2) use of the copper chelate for isolation of the enzymically formed cerebronic acid (2- hydroxy lignoceric acid). For the investigation of oxidative decarboxylation of 2-hydroxy acids, 1-C14-cerebronic acid will be used as the substrate and evolved 14CO2 will be collected. To assay 2-keto acid formation from 2-hydroxy acid, TLC fractionation or Girard reagent extraction will be employed. 2-hydroxy acids are primarily myelin components. The relationship between their metabolism and myelination will be investigated by two approaches: (1) experimental delay in myelination will be produced in developing animals by (a) neonatal hypothyroidism, (b) neonatal hyperphenylalanemia, (c) undernutrition, and (d) neonatal X-ray irradiation. The metabolism of brain 2-hydroxy acid will be studied in these animals. If drugs such as phenobarbital are found to induce the 2-hydroxylation of brain fatty acids, we will examine if these drugs can, in part, counteract the delay of myelination in these experimental animals; (2) we will investigate the effect of an inhibitor of the enzyme for 2-hydroxy acid synthesis on myelination in cultured peripheral nerve cells.